Wearable wound treatment simulation devices

ABSTRACT

A wound treatment simulation device and method of operating thereof are disclosed. The device includes a housing, a simulated wound structure, a pump, a power supply, a sensor, a feedback device, and a microprocessor. The housing is configured to be secured to the live subject and to cover at least a portion of a body of the subject. The wound structure is configured to simulate a structure associated with the type of simulated wound treatment. The at least one feedback device is configured to provide a feedback signal to the live subject. The microprocessor is connected to the sensor and the feedback device. The microprocessor is programmed to operate the feedback device to provide haptic feedback based upon input (e.g. force or pressure) generated from interaction between a treatment provider and the simulated wound structure. The disclosed device may be used to simulate a variety of wound care and treatments.

FIELD OF THE INVENTION

The present invention relates generally to medical treatmentsimulations, and more particularly, to simulation devices for trainingcare providers to manage and provide wound care and treatment.

BACKGROUND OF THE INVENTION

Conventionally, the training process for nursing or medical studentsrelated to patient care and treatment may employ mannequins or staticmodels that do not simulate realistic conditions or provide realisticpatient feedback. This lack of realistic conditions and feedback makesit difficult for nursing or medical students to gain the education andexperience needed to perform proper wound treatments or care whenworking with actual patients. Accordingly, improved systems and devicesare desired for training medical care providers to provide woundtreatment.

SUMMARY OF THE INVENTION

Aspects of the present invention are directed to wound treatmentsimulation systems and devices.

In accordance with one aspect of the present invention, a wearable woundtreatment simulation device is disclosed. The wound treatment simulationdevice includes a housing, a removable wound structure, at least onepump, and a power supply. The housing is configured to be secured to asubject, and the removable wound structure is at least partiallyprovided therein. The removable wound structure has a top surface, abottom surface, and at least one cavity to contain a wound fluidtherein. The cavity is in fluid communication with the top surface. Thepump is driven by the power supply to apply pressure to the wound fluidwithin the cavity. The application of pressure or force to the removablewound structure evacuates the wound fluid from the cavity of the woundstructure to a portion of the top surface of the wound structure.

In accordance with yet another aspect of the present invention, a methodfor operating a wearable wound treatment simulation device is disclosed.The method includes pumping a wound fluid into a cavity in a removablewound structure with a pump. The wound structure is configured to besecurable to a subject and has a top surface adapted to give anappearance and texture of an injury. The cavity is in fluidcommunication with a top surface of the wound structure. The method alsocomprises detecting an application of force or pressure to the woundstructure and determining whether the detected application of force orpressure exceeds a predetermined threshold. Further, when the detectedapplication of force or pressure exceeds the predetermined threshold, anactuator is activated to provide haptic feedback to the subject.

In accordance with yet another aspect of the present invention, awearable wound treatment simulation device is disclosed. The woundtreatment simulation device includes a housing, a removable woundstructure, and an overlay. The housing is configured to be secured to asubject, and the removable wound structure is at least partiallypositioned therein. The wound structure has a top surface and an outerperiphery, the top surface of the wound structure being adapted to givean appearance and texture of an injury. The overlay circumscribes theouter periphery of the wound structure. In addition, the overlaycomprises one or more thermochromic pigments adapted to change in colorbased on a predetermined temperature threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawings, with likeelements having the same reference numerals. When a plurality of similarelements are present, a single reference numeral may be assigned to theplurality of similar elements with a small letter designation referringto specific elements. When referring to the elements collectively or toa non-specific one or more of the elements, the small letter designationmay be dropped. This emphasizes that according to common practice, thevarious features of the drawings are not drawn to scale unless otherwiseindicated. On the contrary, the dimensions of the various features maybe expanded or reduced for clarity. Included in the drawings are thefollowing figures:

FIG. 1 is a diagram illustrating an example wound treatment simulationdevice in accordance with aspects of the present invention;

FIG. 2 is an image illustrating an example top surface layer of thewound treatment simulation device of FIG. 1;

FIG. 3 is a diagram illustrating components of an example housing of thewound treatment simulation device of FIG. 1;

FIG. 4A-4D depict images illustrating examples of a removable woundstructure of the wound treatment simulation device of FIG. 1;

FIG. 5A is a diagram illustrating a fluid flow path of the woundtreatment simulation device of FIG. 1;

FIG. 5B is a diagram illustrating an overlay of the wound treatmentsimulation device of FIG. 5A;

FIG. 6A is an image illustrating a pump and power supply layout of thewound treatment simulation device of FIG. 1;

FIG. 6B is a diagram illustrating an example sensor layout of the woundtreatment simulation device of FIG. 1;

FIG. 6C is an image showing a top view of the wound treatment simulationdevice of FIG. 1, with the wound structure removed.

FIG. 7 is an image illustrating a fluid container layout of the woundtreatment simulation device of FIG. 1;

FIG. 8 is an image illustrating another component of the example housingof the wound treatment simulation device of FIG. 1; and

FIG. 9 is a diagram illustrating an example method of operating thewound treatment simulation device of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the invention are described herein with reference tosimulating specific medical treatments. It will be understood by one ofordinary skill in the art that the example devices described herein maybe used to simulate treatment of a variety of medical conditions, andare not limited to any particular treatment disclosed herein. Othermedical treatments suitable for simulation with the disclosed deviceswill be known to one of ordinary skill in the art from the descriptionherein.

The example devices disclosed herein may be particularly suitable forproviding an enhanced level of realism and/or feedback to the treatmentprovider relative to conventional training devices. Haptic feedback maybe provided to the simulated treatment subject during the simulatedtreatment in order to encourage the subject to mimic realistic patientreactions, and thereby reinforce proper treatment techniques. Likewise,this feedback may be provided to correct treatment errors that the careprovider may otherwise struggle to detect during the simulatedtreatment. The provision of feedback using the example device of thepresent invention may desirably improve the ability of treatmentproviders to comfortably and effectively treat patients.

It will be appreciated that throughout this specification the term woundor injury is to be broadly construed as any damaged region of tissuewhere a wound fluid may or may not be discharged. Further, the termwound or injury includes open and closed wounds in which skin is torn,cut or punctured or where trauma causes a contusion, or any othersuperficial or other conditions or imperfections on the skin of apatient. Examples of such wounds include, but are not limited to, largeor incisional wounds, either as a result of surgery or trauma, mildwounds, acute wounds, lacerations, abrasions, contusions, or the like.Likewise, the term treatment or care provider is to be broadly construedto include any provider of wound care, management or treatment. The termmay include trainees and professionals in the field of medicine, as wellas non-health care professionals.

With reference to the drawings, FIG. 1 illustrates an example woundtreatment simulation device 100 in accordance with aspects of thepresent invention. Device 100 is usable to train medical care providersto treat patients by enabling the performance of simulated medicaltreatment. The device 100 can be adjusted to simulate realisticconditions of wound treatment in various environments (e.g. hospital orother sterile settings, trauma or critical care sites, wilderness,etc.). In general, device 100 can include a housing 110, a removablewound structure 120, and one or more tubes 132, 136. Additional detailsof device 100 are described below.

Housing 110 houses components which simulate the wound, including theremovable wound structure 120. In some examples, housing 110incorporates or is connected to a number of separate components designedto best simulate a wound for treatment. As shown in FIG. 2, device 100may include a durable material 102 covering the housing 110 forattaching the device 100 to the subject. Material 102 may be useful toconceal components of device 100, such as housing 110 and/or tubes132/136, and thereby increase the realistic appearance of device 100.

Housing 110 can be formed from one or more structures which togetherdefine a cavity or space, with the wound structure 120 being at leastpartially (and removably) positioned within the space in the housing110. In the example of FIG. 3, the housing 110 includes multiplestructures which together define the space, including an overlay 112, anarch 104, and rigid ring 114. The operational components of device 100(e.g. sensors, tubes, etc.) are provided within the housing 110 and/orbeneath material 102 of device 100, which thereby provides protectionfor these components and helps conceal wiring and other items.

Housing 110 is configured to be secured to a subject who is playing therole of the patient. The material 102 of housing 110 includes one ormore attachment mechanisms, including but not limited to a pair ofstraps configured to encircle the subject's torso or limb. Straps may beusable to secure device 100 to the subject during the simulatedtreatment. Housing 110 is configured to receive a removable woundstructure 120 therein, e.g., within a space 118 circumscribed by ring114. It will be understood that the shape and size of housing 110 shownin FIG. 3 is merely illustrative of one configuration and may varydepending on the size and shape of the wound structure 120 used and/orthe type of medical condition or wound treatment to be simulated. Forexample, ring 114 may vary in diameter or height based on the size andshape of the wound structure 120. Having a ring 114 that is adjustableto accommodate the wound structure 120 may be desirable to allow foreasy removal and replacement of several wound structures 120 of varyingsizes and shapes over the course of one or more training or educationalsessions.

In the example shown in FIG. 3, ring 114 may be further adapted to beremovably connected to the arch 104 to form housing 110. Ring 114 andarch 104 may be attached, for example, by straps, screws, hook-and-loopfasteners, anchors, adhesives, or double-sided tape, or combinationsthereof. Other suitable attachment mechanisms will be known to one ofordinary skill in the art from the description herein. Arch 104 may alsoinclude flanges 116 having a plurality of apertures 116 a for receivingfastening means, such as screws (not shown), for securing housing 110within material 102. Optionally, the ring 114 and arch 104 may beintegrally formed as a single body of unitary construction that isseparate from the overlay 112. In another example, the overlay 112, ring114, and arch 104 may all be integrally formed as a single body ofunitary construction.

The overlay 112 has an annular shape configured to circumscribe an outerperiphery of the ring 114, thereby defining the space 118 configured toreceive and/or reveal at least a portion of the wound structure 120. Theoverlay 112 may have a diameter selected based on a diameter of the ring114 as well as the shape and size of the wound structure 120 andcomponents thereof.

As best seen in FIGS. 4A-4C, the removable wound structure 120 ispreferably made of material intended to mimic the patient's skin. Thematerial is customizable in coloring and texturing to match a variety ofskin tones. In one example, the material selected to simulate the lookand feel of a patient's skin comprises silicone. Other suitablematerials for use in simulating a patient's skin will be generally knownto one of ordinary skill in the art from the description herein.Furthermore, it will be understood that the selection, appearance, andthickness of layers comprising the wound structure 120 as shown in FIGS.4A-4D is provided for the purpose of illustration, and is not intendedto be limiting.

Removable wound structure 120 is provided on and/or at least partiallywithin housing 110. Wound structure 120 is designed to simulate avariety of wounds or injuries demonstrable on an actual patient,including but not limited to pressure injuries (FIG. 4A), surgicaldehiscence (FIG. 4B), and larger lacerations (FIGS. 4C-4D). Accordingly,wound structure 120 can be positioned on the patient's torso or limb ofinterest based on the simulated medical condition or treatment.

In one example, wound structure 120 includes a top surface 122 and abottom surface 124, with one or more tubes 132/136 attached thereto. Asshown in FIGS. 4A-4D, the top surface 122 is configured to give anappearance and texture of an injury or wound based on the simulatedwound treatment. Although FIGS. 4A-4D depict examples of wounds orinjuries, it should be understood that the wound structure 120 mayinclude any combination of types of wounds or injuries, withoutdeparting from the scope of the invention. Further, the appearance andtexture of wound structure 120 is complex and may be modified to accountfor different tissue types based on the wound treatment to be simulated,including bone, tendon, cartilage, blood vessels, skin, fat, as well asany other organs or other anatomical structures.

In the example of FIG. 1, at least a portion of the top surface 122 ispermeable. For example, as seen in FIG. 1, the top surface 122 can beprovided with one or more openings 128 a, such as holes, slits, orchannels, to allow the flow of fluids from within wound structure 120 tothe simulated wound site (e.g. top surface 122), as well as thetransmittal of negative pressure applied to the wound site to fluidswithin the wound structure 120. Furthermore, the top surface 122 maysimulate a wound type having multiple regions or areas that simulate oneor more stages of wound healing. For example, a portion of the topsurface 122 may be permeable as discussed above, to simulate a region ofthe wound structure 120 that is bleeding heavily, whereas anotherseparate and distinct portion of the top surface 122 may be configuredto simulate, for example, dryness or various other conditions of thewound site (e.g. inflammation). In this way, a treatment provider may betrained to identify and evaluate various conditions regarding the woundstructure 120, such as severity of the wound, areas where various levelsof pressure may be advantageously applied, and any other characteristicsthat may affect the closure and/or healing of a wound or the overallhealth of the patient.

To simulate the discharge of fluids to the top surface 122, the topsurface 122 is in fluid communication with a cavity 128 within woundstructure 120. The cavity 128 is configured to contain wound fluid 136 a(discussed further below) within the removable wound structure 120. Insome examples, cavity 128 is in communication with an opening 124 a ofthe bottom surface 124 of wound structure 120. As seen in FIG. 1, theopening 124 a may be adapted to connect to one or more input tubes132/136 defining a fluid flow path from one or more fluid containers 140(discussed further below) to the cavity 128.

In one example, the one or more tubes 132/136 include a pair of inputtubes 132 leading to a connector 134, and an output tube 136 extendingfrom the connector 134. An example layout of the one or more tubes132/136 is shown in FIG. 6A. As seen in FIGS. 6A and 7, the input tubes132 may be configured to each deliver one or more simulated biologicalfluids 132 a, 132 b, e.g. exudate, blood, etc., from fluid containers140 a, 140 b storing the same, to the wound structure 120 in order tosimulate a wound fluid 136 a. Specifically, the one or more input tubes132 comprises a first input tube and a second input tube connected torespective first 140 a and second 140 b containers.

As shown in FIG. 7, containers 140 may be adapted to store fluid havinga viscosity corresponding to one or more simulated biological fluids 132a, 132 b found in a patient. In one example, the first container 140 astores a first simulated biological fluid 132 a having a first viscosityand the second container 140 b stores a second simulated biologicalfluid 132 b having a second viscosity that is different from the firstviscosity. In operation, the first container 140 a stores simulatedexudate (e.g. pus) during the simulated wound treatment and the secondcontainer 140 b stores simulated blood during the simulated woundtreatment. For example, the simulated exudate 132 aand blood 132 b maybe each formed from a combination of water and one or more viscous gels,lubricants, or dyes to achieve the desired viscosity, flow, and color tosimulate exudate and blood, respectively. The first and second fluidcontainers 140 a, 140 b are each coupled to the one or more input tubes132 in order to provide the simulated exudate and blood 132 a, 132 b,respectively, to the output tube 136, which is coupled to the connector134 on one end and to the wound structure 120 on the other end.

The input tubes 132 are respectively coupled to one or more pumps 150for pushing fluid 132 a, 132 b through the one or more input tubes 132into the output tube 136 during the simulated treatment of the patient.The one or more pumps 150 may be driven by a common power supply 160, asshown in FIG. 6A, or by individual power supplies. In one example, theone or more pumps 150 are peristaltic pumps adapted to apply pressure tothe respective simulated biological fluid 132 a, 132 b in the one ormore containers 140 in order to cause the respective simulatedbiological fluid 132 a, 132 b to flow into and through the one or moreinput tubes 132. In operation, the first simulated biological fluid 132a is pumped through the first input tube and the second simulatedbiological fluid 132 b is pumped through the second input tube. Asillustrated diagrammatically in FIG. 1, the first and second fluids 132a, 132 b may be at least partially immiscible when they are combined toform the wound fluid 136 a that flows through the output tube 136 andinto the cavity 128 of the wound structure 120. This immiscibility maydesirably improve the realism of the simulated wound treatment by bettersimulating wound discharge. The one or more pumps 150 may further applypressure through output tube 136 to the wound fluid 136 a in cavity 128,so that the wound fluid 136 a contained in the cavity 128 of the woundstructure 120 is evacuated through openings 128 a to a portion of thetop surface 122 of the wound structure 120 during the simulated woundtreatment.

Peristaltic pumps may be particular suitable as pumps 150, inasmuch asthey can prevent negative pressure applied to the wound (e.g., duringtreatment involving Vacuum-Assisted Closure (VAC) of the wound) frombeing transmitted to containers 140. Nonetheless, while peristalticpumps are shown in FIG. 6A, it will be understood that other structuresmay be utilized in connection with the one or more containers 140 tocause one or more simulated biological fluids 132 a, 132 b to flow intoand through input tubes 132, output tube 136, and the wound structure120. Suitable pumps, such as hand pumps, for use with the fluidcontainers will be known to one of ordinary skill in the art from thedescription herein.

Finally, the pumps 150 may be electrically coupled to and controlled bymicroprocessor 170, as shown in FIG. 6A. While the microprocessor 170 iswired to the one or more pumps 150 in FIG. 6A, it should be understoodthat the microprocessor 170 may also be wirelessly connected. Throughthe microprocessor 170, a trainer of the care provider may manually orautomatically control the release and/or flow rate of wound fluid 136 ainto cavity 128 and/or out of cavity 128 to the top surface 122 of thewound structure 120 during the simulated wound treatment. For example,the trainer of the care provider may manually or automatically providecontinuous or intermittent pressure via the pumps 150 to cause the oneor more simulated biological fluids 132 a, 132 b to flow into andthrough tubes 132/136 and the wound structure 120, based on the needs ofthe wound being treated or the wound treatment being simulated. Thepressure can be adjusted within a range that has been demonstrated tosimulate realistic conditions of wound fluid discharge.

In some examples, the one or more containers 140, the tubes 132/136,pump 150, power supply 160, and microprocessor 170 are external to orlocated outside of the housing 110, in order to provide simplifiedcontrol over the pumping of fluid out of the one or more containers 140.In these examples, output tube 136 is coupled to the wound structure 120and exits the housing 110 in order to be in communication with the oneor more of container 140 and pump 150. Further, the pump 150, powersupply 160, microprocessor 170, may all be mounted on a plate orsubstrate 138 (FIG. 6A). Plate 138 includes a plurality of openingsthrough which the one or more tubes 132/136 are looped through in orderto establish connection with one or more of the pump 150, power supply160, and microprocessor 170, while maintaining fluid communication withthe one or more containers 140.

When external to housing 110, the fluid components (e.g. tubes 132/136,containers 140, pumps 150) and/or electrical components (e.g. pumps 150,power supply 160, microprocessor 170) of device 100 may be housed in oneor more separate housings adjacent to, suspended over, or worn by thepatient, or may otherwise be concealed from the medical treatmentprovider, in order to enhance the realism of the simulation. It will beunderstood, however, that in other examples, housing 110 may be sized orconfigured to house pump 150 and/or power supply 160 in addition towound structure 120, in order to directly apply pressure to wound fluidin wound structure 120. In these examples, tubes 132/136 and containers140 may be omitted.

Although the example of FIG.1, as described above, depicts fluidcomponents (e.g. cavity 128, tubes 132/136, containers 140, pumps 150)and/or electrical components (e.g. pumps 150, power supply 160), itshould be understood that the fluid components and/or electricalcomponents may be omitted from device 100. In other words, the cavity128; the tubes 132/136; the simulated biological fluids 132 a, 132 b;the containers 140; the pumps 150; and the power supply 160 may each bean optional component of device 100. In these examples, the top surface122 of the simulated wound structure 120 is adapted to give anappearance and texture of an injury, but top surface 122 is notpermeable (FIG. 4A). In such examples, device 100 may include other ofthe components identified herein (such as sensors 180, feedback device190, or fluid passageway 202) to support the simulation of realisticwound treatment.

Referring now to FIGS. 6B-6C, one or more sensors 180 are mounted to thehousing 110. As seen in FIG. 6C, the sensor 180 is mounted on the arch104 and configured to be disposed beneath the wound structure 120 whenthe wound structure is received within the housing 110. Sensor 180detects any application of force or pressure to the wound structure 120during the simulated treatment of the subject. In one example, thesensor 180 includes a force sensor electrically connected tomicroprocessor 170 and configured to detect an application of pressureor force on wound structure 120 during the simulated treatment.Preferably, the force sensors 180 used are force-sensitive resistors(FSRs). FSRs are dynamic resistors that have nearly infinite resistancewhen no force is applied. The resistivity of the FSR decreases,non-linearly, as the force applied increases. As illustrated in FIG. 6B,microprocessor 170 may detect a voltage across the sensors 180 andconvert this voltage value into a detection of an applied force orpressure on wound structure 120. The types and locations of sensors areprovided for the purposes of illustration in FIGS. 6B-6C, and are notintended to be limiting. Suitable pressure or force sensors for use asdescribed above will be readily known or identifiable from thedescription herein. It will be understood that any combination ofsensors may be used, and that additional types and locations of sensorsmay be used, without departing from the scope of the invention. Otherpossible sensors for use in device 100 would be known to one of ordinaryskill in the art.

As shown in FIG. 6B, the microprocessor 170 is in communication withsensors 180 and a feedback device 190. Microprocessor 170 may store(e.g., in an associated memory) one or more predetermined force orpressure thresholds for use in controlling a feedback element, such asfeedback device 190. Microprocessor 170 processes the informationdetected by sensors 180, and determines whether the sensed manipulations(force, pressure, etc.) exceed predetermined thresholds stored bymicroprocessor 170. If microprocessor 170 determines that any thresholdis exceeded, it sends signals to operate feedback device 190 to providefeedback to the subject wearing device 100.

In one example, when a predetermined force threshold is exceeded, hapticfeedback (e.g., vibration feedback) may be provided to the subjectwearing device 100 via the feedback device 190. Haptic feedback may beprovided to the subject via an actuator or vibrating motor for use asfeedback device 190. Suitable haptic feedback generators for use asfeedback device 190 would be known from the description herein. Feedbackdevice 190 may alternatively or additionally be configured to provideother types of feedback, such as auditory feedback.

The feedback device 190 may preferably be positioned outside of andseparately from the housing 110, with sufficient separation that thehaptic feedback is not transmitted to the housing 110 and the treatmentprovider performing the simulated wound treatment cannot sense thathaptic feedback has been provided to the subject. In some examples,feedback device 190 may be positioned on or within a strap used tosecure device 100 to the subject. In other examples, feedback device 190may be coupled to or concealed within material 102, at a locationremoved from housing 110.

In one example operation, a vibratory actuator used as feedback device190 creates haptic feedback or vibration that can be felt by the subjectduring the simulated treatment. Specifically, when the applied force orpressure exceeds a predetermined threshold, microprocessor 170 controlsactuator 190 to provide haptic feedback to the subject based on theapplied force or pressure detected by sensor 180. Microprocessor 170 mayemploy a single threshold/feedback signal, or may utilize multiplethresholds, each associated with a different type of feedback signal(e.g., pulsed or steady feedback, or predetermined series or sequence ofpulses as feedback).

Feedback may be used as a signal to cause the subject to respond to thesimulated treatment in a predetermined way. For example, feedback may beprovided to the patient when the force on wound structure 120 exceeds apredetermined limit. In actual patients, excessive force on a wound canbe a source of discomfort. Accordingly, the detection of force on woundstructure 120 above the predetermined threshold may be used to signalthe subject to simulate discomfort, which may be desirable in ordertrain care providers to limit excessive force on structure and preventdiscomfort in actual patients. The haptic feedback prompts the subjectwearing device 100 to simulate or act in the role of a patient who hasexperienced discomfort from an application of excessive force orpressure to a wound site. The actions or statements performed by thesubject may be predetermined by the subject or by one or more personsresponsible for the simulation, e.g. a trainer of the care provider.This feedback is preferably provided in real time, so that the subjectcan simulate the role of the patient as the detected force or pressureis applied to the device 100.

In one preferred example, as discussed above, the feedback device 190 isa haptic feedback generator, such as an actuator or vibrating motor. Inthis example, a further microprocessor 192 may be configured to actuatethe vibrating motor 190 to provide a haptic feedback to the subject upondetection of the force or pressure beyond a predetermined limit. It willbe understood that although FIG. 6B diagrammatically illustrates thatmultiple microprocessors 170/192 may be used to operate the device 100,a single microprocessor may be used, without departing from the scope ofthe invention.

Device 100 is not limited to the above-described components, but caninclude alternate or additional components as would be understood to oneof ordinary skill in the art in view of the examples below.

As discussed above, housing 110 includes the ring 114, the arch 104, andthe overlay 112. More specifically, overlay 112 of the housing 110 isconfigured to circumscribe an outer periphery of wound structure 120. Asone possibility, overlay 112 and the wound structure 120 may beintegrally formed as a single body of unitary construction. In anotherexample, the overlay 112 may be removable from the wound structure 120following use of device 100. This may be preferable in order to allowthe overlay 112 to be removed and separated from wound structure 120 forcleaning, replacement, or based on the type of medical condition to besimulated. As with the material of the wound structure 120, overlay 112is formed from materials that mimic the feel of the skin of the subject,such as silicone. Other suitable materials for forming overlay 112 willbe known to one of ordinary skill in the art from the descriptionherein.

Referring now to FIGS. 2 and 5A-5B, the overlay 112 and/or ring 114incorporates a fluid passageway 202 embedded therein and through whichfluid travels from a source 206 external to the overlay 112. An examplelayout of the overlay 112 and fluid passageway 202 is provided in FIG.5A. To accommodate fluid passageway 202, overlay 112 may have one ormore channels defined therein for receiving one or more tubes formingthe fluid passageway 202. Alternatively or additionally, ring 114 maydefine one or more channels for receiving one or more tubes forming thefluid passageway 202. In this configuration, the one or more channels ofoverlay 112 and the one or more channels of ring 114 together form aportion of the fluid passageway 202 adapted to receive one or moretubes, such as tubes 204. In other examples, fluid passageway 202 may beentirely embedded within overlay 112 or ring 114.

The fluid passageway 202 desirably extends along the shape of overlay112, e.g., in an annular or circular track. Fluid passageway 202 mayfurther include portions that partially extend radially outward to becoupled to the one or more tubes 204 through which fluid can flow duringthe simulated wound treatment. The one or more tubes 204 have one endcoupled to a fluid container or reservoir 206 that is adapted to storethe fluid. The one or more tubes 204 may also be coupled to a pump 208configured to drive of the fluid through tubes 204 and into the overlay112. In some examples, the one or more tubes 204, container 206, andpump 208 are external to or located outside of the overlay 112 andhousing 110 in order to provide simplified control over the pumping offluid out of the container 206.

Fluid passageway 202 is provided as a heat exchanger, to transmit heator cold from the fluid therein to overlay 112. To this end, fluidpassageway 202 in one example comprises copper tubing, but othersuitable materials for use as promoting heat transfer and forming thefluid passageway 202 would be known to one of ordinary skill in the art.

In operation, the container 206 stores fluid having a specifictemperature during the simulated wound treatment. The simulated fluidmay be, for example, water. The fluid travels through the fluidpassageway 202 and into the overlay 112 in order to manipulate thetemperature of the overlay 112. To this end, the overlay 112 comprisesone or more thermochromic pigments adapted to change in color based on apredetermined temperature threshold, e.g. a range of 60° F. to 75° F.The one or more thermochromic pigments enable the overlay 112 tovisually depict when pressure or force is applied by human hands ontodevice 100. For example, as cold water travels through the fluidpassageway 202, the temperature of the overlay 112 decreases, and theone or more thermochromic pigments changes color accordingly, e.g. to adarker shade. When force or pressure is applied to the overlay 112 byhuman hands, the overlay 112 is heated to a temperature whichcorresponds to the standard temperature of human hands, thereby changingthe color or shade of the one or more thermochromic pigments of theoverlay 112, e.g. to a lighter shade. This “blanching” effect isillustrated in FIG. 5B where a portion 210 of the overlay 112 which camein contact with human hands during the simulated treatment is in adifferent, e.g. lighter, shade when compared to the shade of otherportions of the overlay 112. In this way, the care provider may betrained to evaluate where force or pressure to the wound structure 120is properly applied during treatment.

Referring now to FIG. 9, a method 300 of operating the wound treatmentsimulation device 100 is also provided. The method 300 includes steps ofpumping wound fluid, detecting an application of force, and activatingan actuator based on the application of force. Additional details ofmethod 300 are set forth below with respect to the elements of device100.

In step 302, wound fluid is pumped into a cavity in a wound structure.In an example, wound structure 120 is configured to be securable to asubject. The wound structure 120 includes a top surface 122 adapted togive an appearance and texture of an injury or wound and a cavity 128formed therein. Specifically, the cavity 128 is in fluid communicationwith the top surface 122 of the wound structure 120. Step 302 includespumping wound fluid 136 a into the cavity 128 of the wound structure 120with one or more pumps 150.

In step 304, an application of force or pressure to the wound structureis detected. In an example, sensors 180 detect an application of forceor pressure to the top surface 122 of wound structure 120.

In step 306, it is determined whether the application of force orpressure exceeds a predetermined threshold. In an example,microprocessor 170 detects a voltage across sensors 180 and convertsthis voltage value into a detection of an applied force or pressure.

In step 308, a feedback device is actuated based on the applied force orpressure. In an example, microprocessor 170 actuates feedback device 190when the detected application of force or pressure exceeds thepredetermined threshold.

Method 300 may further include modifying an operation of the one or morepumps 150 in response to detecting the application of force or pressureto the wound structure 120. Additionally, method 300 may includecombining a first simulated biological fluid 132 a having a firstviscosity and a second simulated biological fluid 132 b having a secondviscosity that is different from the first viscosity to generate thewound fluid 136 a, such that the first and second biological fluids 132a, 132 b are at least partially immiscible when combined to form thewound fluid 136 a.

As described above, the wound structure 120 may include an overlay 112having one or more thermochromic pigments adapted to change in colorbased on a predetermined temperature threshold. In these examples,method 300 may further include feeding fluid into and through a fluidpassageway 202 within the overlay 112 in order to change a temperatureof the overlay 112.

FIG. 9 depicts an example method comprising steps that are performedsequentially in the order recited. However, it should be understood fromthe description herein that one or more steps may be omitted and/orperformed out of the described sequence of the process while stillachieving the desired result.

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather, various modifications may be madein the details within the scope and range of equivalents of the claimsand without departing from the invention.

What is claimed:
 1. A wearable wound treatment simulation devicecomprising: a housing configured to be secured to a subject; a removablewound structure at least partially positioned within the housing andhaving a top surface and a bottom surface, the removable wound structurefurther including at least one cavity configured to contain a woundfluid within the removable wound structure, the cavity in fluidcommunication with the top surface of the wound structure; a pumpconfigured to apply pressure to the wound fluid within the cavity; and apower supply configured to drive the pump; wherein an application offorce or pressure to the removable wound structure evacuates the woundfluid from the cavity of the wound structure to a portion of the topsurface.
 2. The device of claim 1, wherein the bottom surface has anopening in communication with the cavity, and further comprising one ormore input tubes configured to be connected with the opening, the one ormore input tubes being respectively connected to one or more containers,the one or more containers each storing a respective simulatedbiological fluid.
 3. The device of claim 2, wherein the pump comprisesone or more peristaltic pumps coupled to respective ones of the one ormore input tubes.
 4. The device of claim 3, wherein the one or moreinput tubes comprises a first input tube and a second input tubeconnected to respective first and second containers, the first containerstoring a first simulated biological fluid having a first viscosity, thesecond container storing a second simulated biological fluid having asecond viscosity that is different from the first viscosity.
 5. Thedevice of claim 4, wherein the first and second biological fluids are atleast partially immiscible when combined to form the wound fluid.
 6. Thedevice of claim 5, wherein the first and second containers and the oneor more peristaltic pumps are located outside of the housing.
 7. Thedevice of claim 1, wherein the top surface of the wound structure isadapted to give an appearance and texture of an injury.
 8. The device ofclaim 1, wherein the top surface includes a plurality of holes throughwhich the wound fluid flows out of the cavity.
 9. The device of claim 1,wherein the wound structure further comprises an overlay, the overlaycircumscribing an outer periphery of the wound structure.
 10. The deviceof claim 9, wherein the overlay comprises one or more thermochromicpigments adapted to change in color based on a predetermined temperaturethreshold.
 11. The device of claim 10, wherein the predeterminedtemperature threshold is in a range of 60° F. to 75° F.
 12. The deviceof claim 10, wherein the overlay incorporates a fluid passagewayembedded therein, the fluid passageway configured to receive fluid froma source external to the overlay.
 13. The device of claim 12, whereinthe fluid passageway comprises copper tubing.
 14. The device of claim 1,further comprising one or more sensors mounted to the housing andelectrically connected to a microprocessor, the one or more sensorsbeing operable to detect the application of force or pressure to theremovable wound structure.
 15. The device of claim 14, wherein themicroprocessor is configured to: determine whether the detectedapplication of force or pressure exceeds a predetermined threshold; andactivate an actuator to provide haptic feedback to the subject when thedetected application of force or pressure exceeds the predeterminedthreshold.
 16. The device of claim 15, wherein the actuator ispositioned separately from the housing, such that the haptic feedback isnot received by the housing.
 17. A method of operating a wound treatmentsimulation device, the steps comprising: pumping a wound fluid into acavity in a wound structure with a pump, the wound structure configuredto be securable to a subject, the cavity in fluid communication with atop surface of the wound structure, the top surface of the woundstructure adapted to give an appearance and texture of an injury;detecting an application of force or pressure to the wound structure;determining whether the detected application of force or pressureexceeds a predetermined threshold; and activating an actuator to providehaptic feedback to the subject when the detected application of force orpressure exceeds the predetermined threshold.
 18. The method of claim17, further comprising modifying an operation of the pump in response todetecting the application of force or pressure to the wound structure.19. The method of claim 17, further comprising combining a firstsimulated biological fluid having a first viscosity and a secondsimulated biological fluid having a second viscosity that is differentfrom the first viscosity to generate the wound fluid, the first andsecond biological fluids being at least partially immiscible whencombined to form the wound fluid.
 20. The method of claim 17, wherein anoverlay of the wound structure comprises one or more thermochromicpigments adapted to change in color based on a predetermined temperaturethreshold, and further comprising feeding fluid into a fluid passagewaywithin the overlay in order to change a temperature of the overlay. 21.A wearable wound treatment simulation device comprising: a housingconfigured to be secured to a subject; a removable wound structure atleast partially positioned within the housing and having a top surfaceand an outer periphery, the top surface of the wound structure beingadapted to give an appearance and texture of an injury; an overlaycircumscribing the outer periphery of the wound structure; is whereinthe overlay comprises one or more thermochromic pigments adapted tochange in color based on a predetermined temperature threshold.
 22. Thedevice of claim 21, wherein the predetermined temperature threshold isin a range of 60° F. to 75° F.
 23. The device of claim 21, wherein theoverlay incorporates a fluid passageway embedded therein, the fluidpassageway configured to receive fluid from a source external to theoverlay.
 24. The device of claim 23, wherein the fluid passagewaycomprises copper tubing.
 25. The device of claim 21, further comprisingone or more sensors mounted to the housing and electrically connected toa microprocessor, the one or more sensors being operable to detect anapplication of force or pressure to the removable wound structure. 26.The device of claim 25, wherein the microprocessor is configured to:determine whether the detected application of force or pressure exceedsa predetermined threshold; and activate an actuator to provide hapticfeedback to the subject when the detected application of force orpressure exceeds the predetermined threshold.
 27. The device of claim26, wherein the actuator is positioned separately from the housing, suchthat the haptic feedback is not received by the housing.